**5. Conclusions**

The engineering modeling of key process parameters, including carburizing temperature, saturated carbon concentration in austenite, diffusion coefficient, and carbon flux, were investigated to meet the requirements of the process parameter model and database for low-pressure vacuum carburization conditions. The following conclusions have been drawn.


**Author Contributions:** All authors contributed equally to this paper and research. Conceptualization, H.W. and Z.W.; data curation, X.A.; formal analysis, Y.T. and J.L.; supervision, Z.W.; writing—review and editing, H.W. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by the National Key Research and Development Program of China (2017YFB0305300).

**Acknowledgments:** The authors would like to express their thanks to teachers and students in the State Key Lab of Rolling and Automation, Northeastern University, for their continuous help and support.

**Conflicts of Interest:** The authors declare no conflict of interest.
